It looks like Microsoft's lawyers will be spending Turkey Day in a Luxembourg courthouse.

The judge overseeing the software giant's appeal of a European Commission ruling has summoned both parties to appear at an "informal hearing" on Thursday. Bo Vesterdorf, president of Europe's Court of First Instance, has spent the past weeks deliberating whether to allow Microsoft to delay various changes to its business practices pending the appeal.

According to a source, the judge appears to be interested in learning more about a settlement announced earlier this month with Novell and a trade group that caused both to withdraw their participation in the EU case. A Microsoft representative did not immediately have a comment on the new hearing.

In March, the European Commission levied a record fine on Microsoft of roughly $650 million (497 million euros). The Commission also ordered Microsoft to offer a version of Windows without a bundled media player and to share more technical information with server rivals.

Microsoft has paid the fine but has asked that the rest of the penalty be suspended pending its appeal. The European Commission has temporarily halted enforcing its decree while Microsoft appeals to the Court of First Instance.